Human mesothelin binders

A human mesothelin (MSLN) binder comprising:

• (a) the six complementarity determining regions (CDRs) of an antibody comprising a heavy chain variable domain (VH) comprising the amino acid sequence set forth in SEQ ID NO:
• 18 and a light chain variable domain (VL) comprising the amino acid sequence set forth in SEQ ID NO:
• 19;
• (b) the six CDRs of an antibody comprising a VH comprising the amino acid sequence set forth in SEQ ID NO:
• 10 and a VL comprising the amino acid sequence set forth in SEQ ID NO:
• 11;
• or,
• (c) the six CDRs of an antibody comprising a VH comprising the amino acid sequence set forth in SEQ ID NO:
• 2, 26, 27, or 28 and a VL comprising the amino acid sequence set forth in SEQ ID NO:
• 3,
• wherein in (a), (b), or (c), the CDRs are defined using the Kabat, Chothia, AbM, ImMunoGeneTics (IMGT), or Contact numbering scheme.